Adsorption of Phosphate in Waste Water with Steel Slag

The oscillation experiments were carried out to study the characteristics behavior of phosphate adsorption on steel slag. The results showed that isothermal adsorption data fitted to both Langmuir and Freundlich equations and the adsorption was preferential type. The theoretical saturated capacity was 0.33 g/kg. Phosphate adsorption kinetics fitted to pseudo-second order Lagergren equation. Equilibrium adsorption amount increased with raising reaction temperature. The adsorption rate was governed by both liquid film diffusion and intra-particle diffusion. Thermodynamics parameters of phosphate adsorption were H0, G0, and S0, which indicated that the adsorption behavior was endothermic, spontaneous and physical process, and temperature elevation promoted adsorption.